Oxychlorination processes for chlorinating olefinic hydrocarbons are well known to the art. The olefin is fed together with oxygen or an oxygen-containing gas and hydrogen chloride over a copper chloride (CuCl.sub.2) catalyst at an elevated temperature. The process can be conducted in either a fixed or fluid bed The copper chloride is supported on an inert material, e.g. alumina. Frequently, in fixed beds the catalyst is provided in layers of varying concentrations and/or with alternating layers of unburdened catalyst support or other inert material. Diluents provide a means of controlling the highly exothermic reaction which, if not controlled, can cause "hot spots" and excessive oxidation losses of the olefin. Patents disclosing various means of conducting this process include Br. 806,570 which uses silicon carbide as diluent: Br. 967,936 which employs graphite as a diluent; U.S. Pat. No. 3,184,515 which also employs graphite, but mixed with the catalyst-bearing particles so that the diluent is present in a higher proportion at the inlet end and the catalyst-bearing particles are in higher proportion at the outlet end of the bed. U.S. Pat. No. 3,240,827 discloses the use of at least 50 volume percent of a macroporous carbon as diluent with the catalyst-bearing particles. The use of an alumina .alpha.-monohydrate as a catalyst support is claimed to permit conducting the oxychlorination reaction at a lower temperature in U.S. Pat. No. 3,454,663. In U.S. Pat. No. 3,699,178 the temperature is controlled by varying the distribution of the catalyst particles so that the larger particles are near the inlet while the smaller are at the outlet of the reactor. In addition to the diluents above-indicated, silica and-glass beads also have been disclosed as useful.
It is also known that the addition of KCl as a promoter with the CuCl.sub.2 employed as a catalyst reduces oxidation losses and the formation of ethyl chloride. Representative of patents which employ potassium chloride as promoter for the catalyst are British Patent 967,936 and U.S. Pat. Nos. 4,123,467: 4,206,180 and 4,424,143.